Hello, I am new to the vintage amp scene so please forgive me for lacking knowledge. Anyway, I was going through a passed relatives house and spotted this amp tucked away. I got it home, disassembled and cleaned up and everything appears to be in great shape. Now I know some of the old components probably need to be replaced, but in my haste I overlooked that and the fact that its rated for 117 volt power and plugged it in and turned it on for about 5 seconds. Just enough to ensure it did function somewhat. Although I didnt touch the case since there is no 3rd pin.

So my questions, I'm quite lost here. Is it bad to run it on my standard 120v sockets? Is there a way to convert it to run on 120v? (I remember seeing someone do this with another) Can someone please tell me the microphone and speaker connection types? I've looked at many connectors and cannot find a match. And anyone who could point me toward documentation like a manual or schematic would be greatly appreciated. Some sort of operation manual would be great. Oh and one last thing, I know it's a good idea to replace some of the old components, but I'm not sure what. Although all of them look good and I suspect this amp was used little.

117 vs 120 is too small of a difference and it doesn't matter. A search online should render a manual somewhere. What happened when you plugged it in?

Just making sure. I remember some guys elsewhere using a variac to get 120v on a 115v outlet and someone else wiring up his amp different to account for the change in voltage. Anyway, I only had it on for 5 seconds but I could hear the transformers hum and the tubes began to warm up. Nothing out of the ordinary I dont think

Edit: kept it on for a little longer and the 6ca4 tube (according to the tube layout diagram) begins making strange popping noises and flashes of light can be seen inside the tube. I'm guessing a bad tube? Or maybe from having no load on it? I didn't keep it on for long after that started, trust me. Oh and the transformer could be heard making a louder hum along with the pops of the tube.

Center ones are just RCAs, one on the right is an old timey coaxial mic connector. Im sure someone knows the real name. The speaker conector is also an old time thing that is long forgotten. I guess that wasnt much help. You can defo get them.

A peek at the rear of the speaker would show which pins were used. One should be a ground/common. If more than two, might be for different speaker impedances or perhaps even a 70-volt output, which would require a transformer on the speaker itself. That's used for long wiring runs or multiple speakers in different locations. Otherwise, you should see the 4/8/or 16 ohm output, which would come from an output transformer on the amp's chassis. The manual should help sort that out.

Lacking a proper connector, you can insert a rod or screw that fits into the sockets and solder or clip your speaker wires to that. Slip a tube or heat shrink over them or tape 'em to keep them from touching one another. You could also skip the pin idea and just solder wires directly to the terminals on the rear. Not as elegant as the correct plug, but it'll work till you locate one.

The mic is an Amphenol connector. I have several from my dad's old parts stash. Also used on some vintage test probes. There's probably adapters to convert it to a more modern mic connector or your own available connector could be soldered on to the rear, like with the speaker, just using a short shielded cable for the hookup.

Besides a sparking tube, expect to find a shorted cap(s) or other failed parts. The transformer will likely fail if testing continues without finding/replacing what's gone bad.

Good info, not home at the moment but I remember it being 3 wires. I think one went to a screw that is used to select the impedance of the speaker, one for postive voltage, and one for ground. I thinkBut I'm not sure where all three wires would go on a speaker. The impedance selection screw selects a different wire from the transformer. Maybe the other wire that I said is postive, isn't what I think it is. Haven't traced it that far yet. Not sure really, haven't really seen too many 3 wire speakers. Unless it's related to XLR?

Update: I was very very wrong Okay so there are 2 speaker connections. One labeled 70 volts and one not. On the non 70 volt connection, it has a ground wire and has the impedance selection wire that picks different wires of the transformer.On the 70 volt connection, it has ground, shares the same impedance selector, and has a 3rd wire from the transformer. So if I figure out this popping/short I could test it.

Don't worry about lack of a speaker load -- with no signal it won't matter, and you are very far away from that. The sparking in the rectifier tube is destructive and needs to be fixed before you do anything else. First you must replace all electrolytic capacitors and any paper capacitors in the unit, as well as the 6CA4 tube which is now ruined. Most likely you have a shorted electrolytic filter capacitor which destroyed the 6CA4.

Before ordering any parts try this: remove the 6CA4 and power up the amplifier. The rest of the tubes should light up. Listen carefully to the power transformer. If if hums loudly or makes any popping sounds don't go any further.

Don't worry about lack of a speaker load -- with no signal it won't matter

How do you know there isn't a signal? The thing isn't working properly yet. There could be hum, intermittent shorts, or a slip of a test probe could introduce an unintended signal. Always have a load, or at least short the output (applies only to tube amplifiers, solid state units have other considerations depending on the circuit they use). Shorting the output is only for the most basic tests like DC voltage levels. It will mess up any AC tests of the output stage or places where the output is included in a feedback loop. For those tests a real load is needed.

It's a good idea to have a load. Also a good idea to leave the volume control turned down. But highly premature in this case -- there is a HUGE DC problem to sort out so no need to worry about AC testing. Certainly a load is irrelevant for the power transformer test with rectifier tube removed.

Good news! Order your electrolytic capacitors and a new 6CA4. There may also be tubular capacitors which need replacement, or they may be film or disk types which will be fine. No more power until this is done.